“We’ve got clams,” says Knud Lingard, bending down to rake up a passel of corbicula—Pacific clams—from the mudflats of Nu‘uanu Reservoir. The clams are just one of the surprises here, high in Nu‘uanu Valley on O‘ahu. The lake, which once supplied drinking water to Honolulu, is also home to cichlids and tilapia. Even more surprising—in a land better known for saltwater fishing—these fresh waters yield channel catfish reaching over 20 pounds.

Lingard, who writes about Hawai‘i’s few freshwater fisheries for Hawaii Fishing News, unofficially presides over fishing season at the reservoir. Since 1958, the state Department of Land and Natural Resources’ Division of Aquatic Resources has stocked the reservoir with these catfish, and three or four times a year they open the gates to anglers. The seasons change year-to-year, but usually run during May, August and November. But when it’s open season, you’ll find Lingard striding jauntily along the banks, joking and giving advice to anyone who’ll listen. Most are regulars.

“What are you using?” Lingard asks a couple of fishermen baiting their hooks.

Farther down, Tony Burgess is using worms for bait, poking around in a bucket of compost. “Worms are sometimes kinda hard to come by,” he says.

“If you have a Filipino friend with fighting chickens,” Lingard jokes, “get what’s under the cages—there’s worms in there.”

He moves on to a group of Laotian men working the next section of the bank. Their 5-gallon bucket is already half full of channel cats, some of which must be almost 20 inches. When Lingard remarks that there’s no water in the bucket, Porter Khamtoun, who teaches a course in Thai cooking, grins and says, “No need water. We’re gonna eat it for lunch.”

Everyone laughs. Khamtoun says this is the best thing about fishing at the reservoir. “Every three months or so, these fish bring us together,” he says, admiring the bucket of cats. Later, he’ll fry them up with chili sauce, and everyone will eat and drink and laugh at one another’s karaoke.

Seeing the Laotians obviously don’t need his help, Lingard moves on to the next group. He’s eager to demonstrate a new fish-finder, a float that’s cast with a small spinning rod and displays on his wristwatch—Dick Tracy-style.